Examine source code of GhostMode

{
  "manifest_version": 3,
  "name": "GhostMode",
  "version": "1.0.0",
  "description": "Dark mode for Google Sheets and Google Docs",
  "permissions": [
    "storage",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "*://*.docs.google.com/*",
    "*://*.google.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.svg",
      "32": "icons/icon16.svg",
      "48": "icons/icon16.svg",
      "128": "icons/icon16.svg"
    }
  },
  "commands": {
    "toggle-ghostmode": {
      "suggested_key": {
        "default": "Ctrl+Shift+D"
      },
      "description": "Toggle GhostMode dark mode"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.docs.google.com/spreadsheets/*",
        "*://*.docs.google.com/document/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "icons/icon16.svg",
    "32": "icons/icon16.svg",
    "48": "icons/icon16.svg",
    "128": "icons/icon16.svg"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "styles/*.css"
      ],
      "matches": [
        "*://*.docs.google.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ghostmode@pv17",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}